It's your form but I think clearing the fields will make this a difficult and annoying form for your users. Consider: the user knows the rule and wants to increase field 1, then decrease field 2. But as soon as they increase field 1, all fields are cleared and they must start again. Also users often do something like this: to decrease 45 to 42, first type 2 giving 425 then remove the 5 giving 42.

Most of the trouble is caused by the calculated fields that include a numeric division operation where the denominator is zero. Whenever you do a division by a field value, you have to use JavaScript to check if the value of the denominator is zero. When you divide by zero, the result can't be formatted as a finite number, so you see the errors you're getting. This is a common problem, so you should be able to find more help with a search, but post again if you get stuck.